Circuit-controller.



No. 796,687. PATENTED AUG. 8, 1905. H. B. WILSON.

CIRCUIT CONTROLLER.

APPLICATION FILED APR.18. 1903.

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Inventor? Howard I3. LULLson.

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UNITED STATES HOWARD B. WILSON, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ATENT OFFICE.

ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CIRCUIT-CONTROLLER.

Specification of Letters Patent.

Patented Aug. 8, 1905.

Application filed April 18,- 1903. Serial No. 153,216.

which a rheostat is employed as a means for controlling the circuit, though some of the features of my invention are capable of use in other relations.

One of the features of my invention is the employment, in connection with an ordinary rheostat, of a switch immersed in a non-conducting fluid for making the final break in the circuit.

Another feature is the employment of a snap-switch for making this final break in the circuit.

Another feature of my invention is a nove rneahanism for opening a circuit on an over- Other features of novelty possessed by my invention will be pointed out in the claims annexed to and forming part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing, which is an elevation, partly in section, illustrating a rheostat containing one embodiment of my invention.

Referring to the drawing, a switch-arm 1, pivoted at 2 and provided with an operatinghandle 3, sweeps over a series of contact-studs 4, which are connected by resistances 5 and a stud 4, disconnected from the other studs, as in the ordinary forms of rheostats. A fixed electromagnet 6 has pole-pieces 7, which cooperate with an armature 8, carried by the switch-arm l, and tend to hold the switcharm in the position shown in the drawing when the electromagnet 6 is energized. A spring 9, connected to a fixed point 10 at one end and to the switch-arm at the other, forms a means for moving the switch-arm to the left as viewed in the drawing when the magnet 6 is deenergized. When the switch-arm is moved to the left, before leaving the last contact 4 it engages with one arm of a bell-crank lever 11, pivoted on the switchboard at 12.

The other arm of the bell-crank lever is slotted at 13 to receive a pin 14, carried at the end of a switch-actuating rod or member 15, and the arm 15 passes through a centrally-located aperture in a cap 16, which closes the upper end of a tube 17. The tube 17 may be formed of metal and provided with a lining 18 of fiber or other insulating material. The lower end of the tube 17 is screwed into a threaded aperture formed in the upper side of a chamber 19.

A screw 20, passing through the top wall of the chamber 19 and insulated therefrom, secures in position a yoke or clip 21, in whicha switch-blade 22 is pivoted. A screw 23, also passing through the upper side of the chamber 19 and insulated therefrom, secures in position a clip 24, with which one end of the switch-blade 22 is adapted to engage and form an electrical connection between the clip 24 and the yoke or clip 21. The yoke 21 and clip 24 are insulated from the walls of the chamber in any suitable manner. The opposite end of the switch-blade 22 is provided with a couple of prongs 25 and 26, between which plays a lug or block 27, extending from the lower end of the rod 15. It will readily be seen that a movement of the rod 15 in one direction will cause the block 27 to engage with the prong 25 and move the switch-blade 22 out of contact with the clip 24, thus breaking the circuit between the clips 21 and 24, and that a subsequent movement of the rod 15 in the opposite direction will cause the block 27 to engage the prong 26 and move the switch-blade 22 back into engagement with the clip 24. To insure a rapid separation between the blade 22 and the clip 24, a lug 28 is formed on the upper side of the switch blade 22, which cooperates with a bowed spring 29, carried by the upper wall of the chamber. In the position shown the spring is under tension, but does not tend to move the switch in one direction or the other; but when an initial movement of the switchblade 22 in the opening direction has taken place the lug 28 will be moved, so that the spring 29, which presses against it with considerable force, will cause the switch-blade 22 and the clip 24 to separate rapidly, as in the ordinary operation of snap-switches. The prongs 25 and 26 are separated somewhat to facilitate this movement.

A helical conductor 30 is placed in the tube 17 surrounding the rod 15 and has one end electrically connected to the clip 21 and the other end secured to a terminal screw 31, which passes through an aperture in the upper end of the tube 17. A piston or lioat which may form a substantially oil-tight [it with the walls of the tube, is slidingly mounted on the rod 15 near the upper end of the tube 17. threaded, as shown, and a pair of nuts 15', which may be jammed together to lock them in position, form an adjustable stop against which the piston abuts. The receptacle formed by the chamber 15) and that portion of the tube 17 below the piston 32 is filled with some non-conducting fluid, such as transil-oil. It will readily be understood that the 1. assage of current through the helical conductor 30 will cause the liquid in the tube and chamber to be heated and to expand, thus moving the piston upward. By properly proportioning the parts the passage of a current of a predetermined strength for a predetermined interval will cause the piston 32 and the rod 15 to be moved su'l'liciently to opcrate to move the switch-blade 22 out of contact with the clip 24 and open the circuit at that point. The sliding connection between the piston and the rod 15 allows the rod to be moved by the lever to operate the switch without moving the piston. No arcing will take place under ordinary circumstances between the blade 22 and clip 2 .1, as they operate in a noxrconducting fluid.

The particular embodiment of my invention which I have illustrated in the drawing is intended to be used as a motor-starting apparatus. One side of the line is connected to a bindingqiost A conductor 34: extends from the post to the screw 23. From thence the circuit extends through the clip 24, blade 22, yoke 21, helical conductor 30, to the terminal 31. A conductor 35 connects the terminal 31 with the pivot 2. A conductor 36 extends from the pivot 2 to the bindingpost 87. This conductor includes the wind ings of the electromagnet 6. The bindingpost 37 is connected with one side of the field of the motor. The armature-current passes from the pivot 2 through the switch-arm 1 to the appropriate contact-stud of the rheostat, and from the no-resistance stud of the rheostat it passes through a line 38, leading to a binding-post 39, which is in circuit with the armature.

The operation of my device is as follows: Assuming switch-arm 1 to be at the extreme left in contact with the dead-contact 4t and the switch-blade 22 in the open position, the initial movement of the switch-arm 1 to the right will oscillate the bell-crank lever 11, which in turn will reciprocate the rod 15 and close the switch 22. hen the switch is closed, a circuit-will be established through the field of the motor. This will energize the The upper portion of the rod 15 is coil 6. When the switch-arm 1 is movedstill farther and engages with the stud 4:, current will begin to flow through the armature through the resistances 5. When the switcharm 1 is thrown over to the position shown in the drawing, all of the resistances 5 will be cut out and the normal condition of operation will be attained. The switch-arm is then held in that position by the attraction between the pole-pieces? and the armature 8. If the current passing through the helical conductor 30 exceeds a predeterminedamount for a predetermined time, the oil in the chamber and tube 17 will be expanded suliiciently to move the piston 32 and open the switch-blade This opens the circuitboth of the held and the armature. The electrormignet (3 will then be deenergizedand the switch-arm 1 will be moved to the starting position by the spring 9. I 1 the current does not become excessive, but for any other reason it is desired to open the circuit, the switch-arm 1 may be manually moved by grasping the handle 3, and as the arm is moved off from the contact 4 at the left the hell-crank lever will be oscillated and the switch-blade 22 opened. In either event the circuit will be broken between the switchblade 22 and the clip 24. before the switchblade 1 moves ofl the last contact 1.

It will 01" course be understood that in practice the mechanism described and illustrated in the specification and drawing may be varied in construction and proportion to meet the conditions under which it may be used without in any way derjiarting from the spirit of my invention.

\Vhat .I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a rheostat, a series of contact-studs, a switch-arm moving along said studs, an arm pivoted in a position to be engaged and oseillated by the switch-arm, a snap-switch, and means connecting the pivoted arm and the snap-switch whereby the movement of the piv oted arm in one direction will open the snapswitch, and a movement of the arm in the opposite direction will close the switch.

2. In combination, a vessel, a quantity of liquid and a piston contained therein, a switcl actuating member, and a connection between the piston and the switch-actuating member so arranged that a movement of the piston in one direction only will operate the switchactuating member.

3. In combination, a body of liquid, a member moving in response to changes in volume of the liquid, aswitch, andmeans connecting the switch and said member for operating the switch when the member is moved in one direction but not when the member is moved in the opposite direction.

I. In combination, an electric circuit, a switch in said circuit, a body of liquid, means for heating the liquid proportionally to the current passing through the circuit to thereby change the volume of the liquid, and means actuated by the change in volume of the liquid produced by a predetermined condition of current-flow in said circuit for operating the switch in said circuit.

5. In combination, a body of liquid, a member to be actuated located in said liquid, means For electrically heating said liquid, and means responsive to a change in temperature of said liquid for actuating said member to be actua-ted.

6. In combination, an insulating liquid, a portion of an electric circuit includinga switch located in said liquid, and means responsive to the change in volume of said liquid due to the heating produced by the passage of a pre-' determined current through said circuit for operating said switch.

7. In combination, a body of liquid, a portion of an electric circuit including a switch located in said liquid, and means responsive to a change in volume of the liquid produced by the current passing through said circuit for operating said switch.

8. In combination, abody of liquid, aswitch located in said liquid, and means responsive to a change in the physical condition of the liquid produced by the current passing through said switch for operating said switch.

9. A receptacle, an insulating liquid con tained therein, a switch immersed in said liquid, a conductor in circuit with said switch for heating said liquid, a piston or float moved by the changes in volume of said liquid due to the heating effect of said conductor, and mechanism connecting the float or piston and the switch for operating the switch upon a predetermined movement of the piston or float.

10. In combination, a body of liquid, a

switch located in said liquid, a switch-actuat-' ing rod or mcmber, means external of the liquid for operating said switch-actuating member, and means separate therefrom for operating the switch-actuating rod or member upon a change in volume of the liquid produced by the passage of an excess of current through the switch and heating-conductor.

11. A circuit-breaker comprising a body of liquid, a heating-conductor forming a portion of a circuit to be broken and arranged to heat the liquid, and means responsive to a prede termined change in temperature of the liquid for breaking the circuit.

12. A circuit-breaker comprising a body of liquid, a heating-conductor forming a portion of the circuit to be broken and arranged to heat the liquid, and means responsive to the change in volume of said liquid produced by the passage of an excess of current for a predetermined period for breaking the circuit through said conductor.

13. In combination, a receptacle having a portion of comparatively large cross-section and another portion of comparatively small cross-section, a liquid in said receptacle, an electric switch located in the portion having a larger cross-section, a heating-cond uctor arranged to heat the liquid in the portion having the smaller cross-section, a switch-actuating member, and means located in said portion having the smaller cross-section for operating said member upon a change of volume of the liquid.

14:. An electric circuit, a body of fluid heated by the current passing through said circuit, and means controlled by the liquid for interrupting said circuit upon the passage of an excess of current through it.

15. In combination, a rheostat, a switcharm therefor, a snap-switch operated in one way by the movement of the switch-arm away from its initial position and in the other direction by its movement into its initial position, and automatic means for operating said switch upon a predetermined condition of current-flow.

In witness whereof I have hereunto set my hand this 15th day of April, 1903.

HOWARD B. WILSON.

Witnesses:

BENJAMIN B. HULL, MARGARET E. WOOLLEY. 

